Deciduous trees can provide crucial bushfire protection in rural Australia

4/2/2017

Deciduous trees act as a fire retardant and are often the reason why some houses survive a bushfire when neighbouring houses are burnt. Why do they provide fire protection and how can they be used in rural areas to make summers safer?

The Marysville Country Bakery - Cafe survived the 2009 fires virtually intact. Note the deciduous trees on either side.

The Weekend Australian Feb 21 2009

A former owner of the Crossways Hotel in Marysville, which survived the fire in 2009, Mr Lawrey is advising residents to plant European trees around their houses rather than eucalypts. "European trees saved my house," he said. "The embers that landed in the trees had time to burn out".
If they land in eucalypts, they burn immediately. "He said all three commercial buildings left standing in Marysville had European trees nearby. They really cooled the fire down when it reached them"

Children playing in the cool air generated by a London Plane tree in the Adelaide Botanical Gardens

The benefits of deciduous plants.

Deciduous plants are very useful around the home and in public places not only because they add to the ambient beauty but also because they provide cooling shade in the summer and let the sunlight through in the winter.

Evergreen trees are unable to provide this shade contrast. In fact Australian natives often do the reverse and let more sunlight through in the summer by turning the flat surface of their leaves away from the sun to reduce transpiration loss. Some natives like eucalypts let in more light by shedding their leaves during the very hot dry periods.

Deciduous trees cool the air around them through transpiration. The water held in leaves is released from the stomata as water vapour. A Similar evaporative cooling principle is used in air-conditioners. On a hot day it is possible to feel the temperature drop a few degrees as you walk from the shade of native trees under deciduous trees. I experienced this tangible temperature change recently on a visit to the Adelaide Botanic gardens on a 38 degree day walking beneath a very large London Plane tree. It wasn't a coincidence that many more visitors to the gardens that day were seated under this shady tree than could be seen in the rest of the gardens.

Additional benefits of a deciduous trees and vines are fruit & nuts; timber for craft, furniture, and building; firewood, attractive flowers and autumn foliage; shade; privacy screening and as mentioned before they let in the winter sunlight which can make a cold room warmer and dry a boggy track.

Radiant heat is invisible and extends well beyond the flames of a fire

How deciduous plants provide protection from bushfires.

Deciduous plants are fire retarding because they have high moisture content in their leaves without the flammable oils. They can provide excellent fire protection in four ways.

1. By shielding buildings from the damaging effects of a fire's radiant heat.

A vegetation screen between a building and an oncoming fire can prevent windows shattering, plastics melting and timbers buckling by reducing the radiant heat emanating from the fire. Radiant heat is short and intense because a bushfire front takes only 30 - 40 seconds to pass through. In extreme fire conditions a house has to withstand temperatures of up to 1200 degrees for about two minutes if it is exposed to the full un-shielded intensity of the radiant heat.
Native trees and shrubs will also shield a house from radiant heat.

Glowing embers clearly visible in advance of a fire. Deciduous trees would absorb many of these

2. By catching flying glowing embers before they reach the home.

It's not uncommon to hear stories about people who stayed to save their homes and later celebrated with friends at the pub only to return to a smouldering ruin. The cause of this enormous disappointment and personal tragedy are the airborne embers of burning leaves and bark that cause spot fires ahead of a fire-front and continue to fall after a fire has passed.

Many airborne embers become caught up in the foliage of surrounding trees. If they become caught in deciduous trees they're no longer likely to be a threat.

3. By 'snuffing' out the embers they catch.

The water filled leaves of deciduous trees will cool and extinguish glowing embers in the same way that water puts out a fire. The leaves on the side nearest to the fire-front will be scorched as they take the heat out of the embers but they won't ignite and add to the intensity of the fire.
A eucalypt or a pine could accelerate the fire and burn because they releasing volatile oils which can spontaneously ignite at temperatures above 60 degrees.

2009 WA fires at Ferndale. The deciduous trees saved this home

4. The leaf litter isn't flammable and breaks down rapidly to humus, improving the soils ability to hold moisture.

Have you ever noticed the smouldering heaps of raked deciduous leaves in the late Autumn? Some over zealous gardeners try to burn them when its much easier to turn them into compost. They are difficult to burn and this feature will stop a fire from spreading. This was observed after the devastating Western Australian fires of 2009 by a firefighter defending a house at Ferndale.

"Every ember that fell on the side of the house that was planted with Blue Gums started a fire in the fallen gum leaves.
Every ember that fell on the other side, amongst the poplar leaves, just petered out.
There was a 100 percent difference.

A ring of deciduous trees was an effective barrier against this fire

Where to plant for fire protection.

The key fire sectors are north, north west, west and south west. These are the directions that a fire will come from and also the sides of a property best planted with deciduous trees or vines.

Bad fire days are always associated with strong northerly or north westerly winds. North winds are warm in summer as they blow across the northern deserts before they reach the southern states. These warmed gusty winds can strip the moisture from leaves and cause less hardy plants to wilt.

Wind directions can change. A cool change is always very welcome when it brings relief from extreme heat, but it can turn a fire to the east. If a fire is coming from the north with a narrow front and is turned toward the east by a westerly change, the long eastern edge of the fire becomes the new and much longer fire front.

To protect your home against all these possibilities imagine a semicircular zone from the south-west extending to the north and plant this zone with deciduous plants to guard against the unpredictable nature of fire. Choose trees appropriate to the size of the space available because large deciduous trees can dry out garden beds and cause structural damage if planted too close to a building.

Autumn colour in a diverse mix of deciduous trees

What deciduous plants are suitable for your country property.

When choosing suitable plants you will have more success if you factor in your annual rainfall, aspect (south & east facing positions and slopes are cooler than north & west facing), drainage and soil type. This knowledge is critical and can make the difference between success and failure whether you are planting hardy natives or exotic deciduous trees. This knowledge is also very useful when you visit your local nursery.
Generally in dry areas drought tolerant plants will cope with a long dry spell and hold on to their leaf moisture in the dry months. This is a very important feature if they are to function as a fire shield.

I have added some potential uses and cautionary notes in brackets below as an alert to help your choice and avoid future regrets. Always check the eventual size of the trees you're planting and keep them at least 1.5 times their mature height from any structures with foundations. Very large trees like the Beeches, some larger maple species, Weeping Willow and London Plane can cause structural damage and their roots can lift paved areas. On the brighter side, an avenue of London Plane trees planted in the fire sector will provide a very effective fire shield from 40 meters away from a homestead.

The following genera of deciduous trees prefer moist soils.
They are unsuitable as fire shields in dry climates unless they are in a moist gully or well irrigated:
Willows (an environmental weed on waterways, one species used traditionally to make cricket bats).
Poplars (buy non suckering cultivars, valuable timber).
Most oaks (valuable timber, acorns are edible if the bitter tannins are removed by repeated boiling).
Maples (valuable timber).
Birches (valuable timber).
Beech (valuable timber, edible nuts).

The following genera of deciduous trees are hardy and tolerate very dry conditions:
Ash (Desert Ash is very hardy but potentially a weed, grafted cultivars like the Claret Ash are not weedy, valuable timber).
Plane (valuable timber, the roots are deep, invasive and potentially damaging).
Hawthorn (spread by birds and can become an environmental weed),
Black Locust (boat building timber, firewood, will sucker).
Honey Locust (valuable hardwood)

A well managed orchard to the north or north west of the family home provides an excellent fire break and radiant heat shield. It will also cool the air on hot summer days

The following common fruit and nut varieties will cope well with long dry periods when established:
For a good crop in dryer locations drip irrigation is recommended.

Quince (will sucker), pomegranate, plum, persimmon, pecan, pear, mulberry, fig (will sucker), apricot and almond.

Apple, peach, nectarine are less drought tolerant but will still survive without irrigation if 'the dry' is not too prolonged.

The luxurious foliage of a grape vine will trap and cool airborne embers

Walnut (Black Walnut provides valuable timber), hazelnut, chestnut and cherry definitely need moist soil with good drainage and prefer cooler summers

Ornamental pears and ornamental prunus are a very useful medium sized trees that will cope with drought and poor drainage. The prunus genus which includes almond, apricot and plum are tough and adaptable to most soils particularly if they are grafted onto plum rootstock.

I have included this link to 'The ultimate guide to fruit & ornamental trees' published by Flemmings. It should answer any questions you may have about the suitability of different trees. Flemmings are a well known nursery dynasty that have researched and published this excellent guide to trees that they sell through retail outlets. There are cheaper wholesalers of deciduous and fruit trees, so it is definitely worth shopping around.

Ornamental and fruiting grape vines are also very hardy and can be used as a trellised fire shield.

Deciduous trees provide many benefits around human settlements but reducing the fire risk is arguably a most critical asset that should be considered for every rural home.

Planting back the indigenous and native vegetation in rural and urban areas is essential to protect our indigenous flora and fauna and to restore the resilience of the natural environment to change, but it would be foolish to ignore the advantages that deciduous plants offer to human safety in the advent of a serious fire.

You might also like these articles on bushfire safety by Stephen Murphy;

'Maintaining native gardens for fire safety in rural southern Australia'

'Farm plantations can reduce bushfire risk'

Bushfires 2020 - making families safe in their country homes

58 Comments

Valerie Hathaway

26/11/2017 09:52:41 am

I have a love of Ribinia deciduous trees & would love to create an avenue of them on my daughter & son inlaws property at Woodstock NSW. I found the article very informative, thankyou so much.

locust

26/11/2017 11:07:15 am

Hi Valerie
Robinia (Black Locust) & Gleditsia (Honey Locust) are both beautiful and very hardy trees that prefer a well drained soil. Robinia cultivars have a tendency to sucker, but there may be new rootstocks that are less likely. Check with the nursery for the most suitable rootstocks.
Good luck with the avenue planting, it will look amazing.
Steve

stephen link

4/2/2019 09:46:48 pm

This was a very Interesting read. I am Surprised that towns in rural/bushfire prone areas do not heed this advice (One only needs to look at the 2009 VIC bushfires to see). I think this valuable information should be widely distributed so that people can plant all around their properties, deciduous trees to protect against the devasting fires. I Think that this article needs to be shared and distributed so that people can be educated about the benefits of planting deciduous european trees on their properties to protect against bushfires. What a fascinating read this was. I will share this info with many people to come. Thank you for infroming me about this

- Stephen

Steve

5/2/2019 08:33:05 am

Thanks Stephen for your encouraging comments. I agree that it does seem an obvious strategy in bush fire prone areas. There is plenty of anecdotal evidence of houses that survived fires to support the logical benefits of planting deciduous trees around rural homes.

I would take it a step further and suggest that towns in fire prone areas would benefit from street plantings and barrier plantings in strategic fire sectors.

I am also an advocate of protecting our natural areas and the wildlife that depend on them, but the proposal of planting deciduous trees for fire protection should be discussed more and considered as an important life saving choice that people could make.when they live in fire prone areas.

bronwyn

18/2/2019 03:20:23 am

Thank you for your article - 10 years after losing our home on Black Saturday l too am about too share my experience of what l witnessed after coming "home" .
Just how Eurpoean planting and hedging protected some homes, actually where we now live the first owner has planted what are now big old chestnut trees on the edge of the forest as a "living fire buffer". We are adding too this type of planting as part of our Fire Plan as we live amougst Mountian Ash and Tree Ferns ( which we love ) but see the benefits of planting low fuel trees that are also great climbing trees for our children.
Sadly when l have shared my experince and thoughts like using this planting too protect townships , homes even around Conservation areas it comes with such a backlash not even some in our fire agencies were open too this.
My heartaches when l see another family losing their home to fire or another fire that can not be contained.
Planting Fire buffers could also benefit our wonderful firefighters as well to help slow or stop the fire from getting out of control.
With a tree that create's shade, imroves the soil and can protect us all from fire l have too wonder why this isn't part of all our fire plans?

Steve

19/2/2019 02:11:58 pm

Hi Bronwyn,
You have experienced a personal tragedy that most of us just read about. It must have been a very difficult time for you and your family. It sounds like you have learnt a lot from what you have observed and thank you for sharing that with me.

The planting of deciduous trees around human settlements has many benefits and as you say an important one is bushfire survival. There is plenty of anecdotal evidence like your own to support this proposal but I think we do need some solid academic studies to get the powers that be to take it more seriously.

Until then keep planting deciduous trees around your country home. It sounds like you have found a beautiful place to live.

Justine

25/2/2019 01:23:24 pm

Thank you for your excellent and informative article. I am curious about one issue; the planning permit conditions that state that tree canopies within the defencible area should be not connected.
My gut feeling is that it is the 'avenue'effect of the line of moist deciduous trees that would provide the best protection against embers and radiant heat - what do you think?

Steve

2/3/2019 01:48:55 pm

Hi Justine,
Thanks for your question.

I agree that a continuous hedge of foliage provided by an avenue of deciduous trees would be more effective than an avenue with separated tree canopies. Wind velocities will increase as it is funneled through the spaces between the canopies.
These stronger winds would potentially carry more embers in a fire situation

Having said that, here are some suggestions and cautions;

1. Plant a two row avenue of staggered trees. Therefore trees in the second row are planted opposite the gap between the trees in the first row. This would provide an 'effective continuous canopy' while maintaining canopy separation.

2. Its best not to plant tall trees, even tall deciduous trees within the 10m recommended defendable zone (See the CFA PDF - Landscaping for Bushfire:Garden design and Plant selection - pages 12 +).
Even though they are much less flammable than many tall native species, roots can still crack foundations and their fallen leaves will fill spoutings.

3. A useful rule of thumb is to plant all plants at least 1.5 times their mature height away from buildings to avoid structural damage, falling tree damage and the build up of dead leaves in spouts and against buildings. So a 10m tall tree would be safer if planted 15 meters from a house and sheds.

Using this rule of thumb an avenue of London Plane trees (potentially grows to 30m tall) would be planted no closer than 45 from a house or shedding.

The wind shelter and fire benefits would extend to 2 - 10 times the height of these Plane trees which is 60m to 300m from the trees. This is a well established figure for the protection zone behind any wildbreak or shelter belt.

I hope that helps a little with your planning

Caroline Johnson

23/12/2019 06:06:40 pm

We have giant elm trees all around our old cottage. you know what...if the floor cracks, I dont mind cos the trees will protect us in a fire as the Fire Service says, and i love them on 40 degree days as they keep us cool. SO WHAT if your slab cracks. its not the end of the world. I do not agree with this 1.5 x height of tree from house rule. Those plantings will not keep your home cool or improve the amenity of your verandah. Oour new extension was desighned on posts to not disturb the tree roots and we love living under them. So what if a bough falls on the roof. Insurance covers it and they give us too much money for it. with climate change we need to plant way more trees.

Sue

5/3/2019 01:46:21 pm

This sounds like very sensible advice. Do you have any recommendations about how to keep newly planted deciduous (European) or Australian native rainforest trees alive through the increasingly brutal hot, dry summers of climate change? We have tried several times to implement your ideas, but our trees just seem to fry during the summer - and the only things we can keep alive are native i.e.. flammable trees and shrubs.

Steve

5/3/2019 06:48:41 pm

Hi Sue,
That’s very disappointing to read that your trees struggle to survive the long hot summers.

Without knowing your site I can only make some general comments. I’ll assume you have chosen trees that are suited to your soul, drainage and climate.

- deciduous trees will do much better if they are bare rooted and smaller when you plant. Avoid buying deciduous trees in pots as their roots will be compromised and won’t develop properly after planting.
Native trees should be purchased in tubes (Hiko, Lannen, square forestry tubes) and never round pots because of poor root structure in the latter.
- add plenty of humus, compost or coir (up to 20%) to your soil when you plant to help retain the soil moisture in summer.
- install a drip system with 12mm poly pipe after planting and water well fortnightly over the dry periods. Alternatively bury a 75mm watering pipe from the top to bottom of the planting hole to enable more effective watering in Summer. It directs the water deeper to where the tree needs it.
- a better long term solution to watering is to set up swale drains on contour to collect and channel runoff to your trees.
- mulch 1-2 m wide and 100mm deep in September to keep the soil cool and minimise drying over late spring early summer.

I hope that helps get you trees through their first three summers. They should be established enough to survive most seasons after that.

Adam

1/3/2020 08:48:56 am

Have you tried deciduous Mediterraen trees that are more heat tolerant? Or even the few australian decicduous trees like Tona or Melia?

Adam.

Steve

8/3/2020 12:19:50 pm

Hi Adam,
I've done some background reading on Toona ciliata an it looks like a useful tree for permaculture, providing a good quality honey, timber and even aromatic oils from the fruit. Agroforestry expert Rowan Reid features it in his new book 'Heartwood'.

As to its value as a fire break, this Hawaiian reference suggests that it is, http://old.worldagroforestry.org/treedb2/speciesprofile.php?Spid=1649 However further research would be advisable before you rely on the Red Cedar to protect your property.

White Cedar, Melia azedarach; appears to be quite a useful fire retardant tree. I see that its listed on The Australian Plants Society's list of 'Fire resistant and Retardant plants'. It also has the benefit of being very drought resistant and the berries can be used to make an organic insecticide.

Other Australian deciduous trees like the illawarra flame tree, Brachychiton acerifolius; and others of the kurrajong family are also useful fire retardant tree species. I found a number of references recommending then after a quick google search.

rick

6/3/2019 09:21:04 am

I googled "Marysville bushfires" and followed a link to this site. Very interesting reading. I agree, from experience, with the shade and cooling benefits of deciduous European trees. I can't comment on the bushfire retardant benefits, but it seems to make sense.
Back to the Marysville images. Looking at aerial shots of the town and the total devastation, I was struck, even before reading this article, that trees surrounding destroyed houses appeared to suffer no damage. I'm watching ABC 9am news and a report on the fires at Yinnar. the vision showed destroyed properties, but trees undamaged.
It seems to me that deciduous trees may offer a benefit as you have stated but they should not be relied on for protection.
I would be interested in your comments

Steve

13/3/2019 06:18:08 pm

Thanks for your thoughtful comments and interesting observations rick.

I agree that fire protection is a complex issue and that there isn't one solution that provides a magic bullet answer - I wish there was.

I believe that barriers of deciduous trees protecting rural properties would reduce the risk of death and damage from fire. I'm advocating planting them at a safe distance of 1.5 times their mature height from buildings so that leaf drop and falling limbs in a high wind fire situation aren't a threat to people or homes. Even an irrigated orchard north of the home will have a cooling effect and provide some radiant heat protection to 2 - 4 meters above ground level.

Even without the fire suppression deciduous trees provide many other benefits that make them worth planting - summer shade/winter sunlight, nuts & fruit, craft and building timbers, aesthetics.

More observations of photographic records, of the sort that you have made, would be most instructive and would help to build the anecdotal evidence for the fire benefits of planting deciduous trees.

We may need some PhD students to study the evidence to build its credibility.

Peta Townsing link

26/8/2019 12:55:48 am

Hi Steve,
A friend sent me a link to your blog which I found to be very encouraging with respect to the role that deciduous trees can play for those of us who live in bushfire-prone areas. I'm in SW WA in a small town of Balingup. Since 2003 we have had several large bushfires near us that fortunately did not come closer than 8 km away. There is always the chance that one will come near. Our area has a record, too, of deciduous trees playing a role in saving properties. In fact you quoted the result that deciduous trees played in the Ferndale Fire where a homestead had the flames go around because of the trees. Rick wondered why with aerial pics the houses are gone but the trees often appear to be untouched. This would be the result of ember attack. The flame front has gone through but embers can come before, during and after a blaze and can travel kms in severe forest fires with long unburnt fuels. Once the flames have passed through the embers can still be coming and/or several embers have already landed in spots say at a corner of the veranda and smoulder or some have got into the roof space or into rooms via vents. After awhile these embers can ignite the building and the house will burn, often from the inside. The trees though if they have only been scorched by the flames will be ok, but the house can burn to the ground. Another point and this was shown at the Yarloop Fire when timber houses quite close to each other in several of the streets had one house catch alight which then caught the adjacent one. So it becomes house to house conflagration. That's why it is important for people not to relax once the fire front goes through. After the fire firefighters and homeowners - if they are defending their properties - need to patrol and be alert to any flareup and quench it fast. Jack Cohen is an eminent retired researcher, very practical, who has studied why houses burn down. More often than not it is the embers that cause the house to burn down. Here is a link: https://www.hcn.org/articles/the-loss-of-homes-to-wildfire-is-as-much-a-sociopolitical-problem-as-it-is-a-physical This concept is important and is endorsed by the NFPA in the US, but you will find fire authorities in Australia are aware of this phenomenon. We have 3 sets of mops and buckets (metal) for each of our sheds on our property. Wet the mop and put out the embers. Deciduous trees are a great idea and will help shield from embers as well.

Steve

26/8/2019 12:02:13 pm

Hi Peta,
thank you for those important comments.
Embers do start house fires after bushfires have passed through - I have heard many similar heartbreaking stories.

Your link to the devastating effects of American wildfires and how 'firebrands' (embers) are considered to be a major cause of home loss is very valuable.

Fire expert Jack Cohen puts his case clearly in the article. Home owners can't rely on the fire authorities providing support after a fire has passed through because they're very likely busy at the fire front.

If home owners focus on putting out small fires around the house with a bucket of water and a mop they will save lives and homes

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1/4/2019 11:55:46 pm

Hi stephen,
I believe that barriers of deciduous trees protecting rural properties would reduce the risk of death and damage from fire. I'm advocating planting them at a safe distance of 1.5 times their mature height from buildings so that leaf drop and falling limbs in a high wind fire situation aren't a threat to people or homes. Even an irrigated orchard north of the home will have a cooling effect and provide some radiant heat protection to 2 - 4 meters above ground level.
Thanks.

Bronwyn

12/4/2019 09:44:06 am

Hello Stephen,

l have just sent your link to Emergency leaders for climate action. A bigger discussion needs to start NOW regarding planting deciduous trees hedging as a living fire buffer .. not only for private property but used as buffer to protect around townships or on the edges of bushland.

We need real leadership that allows discussions like these, l have tried to share my experince of the aftermath of returning home after Black Saturday, my home was lost, but it was

Bronwyn

12/4/2019 10:27:08 am

Sorry my little girl pressed the submit button before l finished my comment...

Coming home it was obvious how this planting protected homes .. l am so pleased that your article is creating a much needed discussion, as what l have seen this year is heartbreaking, another fire not contained and more homes lost.

Every year we keep putting the wet stuff on the red stuff with the same results .. As a mother who has lost her home to fire l have tried so hard to share this information with our fire agencies, but everytime l am dismissed.

It would take real leadership to allow more fresh ideas like this one .

It would take real leadership to allow community involvement.

Thank you for allowing me once more to leave a comment .

l hope passing on your link to the Emergency leaders for climate change might start a further discussion .

Steve

15/4/2019 12:54:00 pm

Hi Bronwyn,
Your passion, courage and persistence will eventually win the day. Its hard for me to understand why there would be so much resistance to the idea of planting deciduous trees for bush fire protection.

Is it related to conserving our native flora within the 10/30 rule zones? Many of our native grassland flora could still flourish under deciduous trees with sympathetic management strategies like minimum disturbance and light mulching. They will also reduce fire risk because they are often green through the summer (E.g. Kangaroo Grass, Themeda triandra and Weeping grass, Microlaena stipoides) will green up to summer rain events.

Keep up the your great works and I hope doors begin to open for you

Peter

14/1/2020 05:44:51 pm

This sort of tree planting does not work in most situations .My brothers orchard of fruit and nut trees was turned to ash along with his house and sheds and all the trees on his farm .A gully running across the back of this house may have caused a draught way from the house .Or just sheer luck .I think its very wrong to suggest planting any trees close to a house .30 years CFS experience tells me the only thing to save a house is clear ground or very low moisture filled plants ...

ingilis dili kurslari link

4/10/2019 03:34:39 am

If they land in eucalypts, they burn immediately. "He said all three commercial buildings left standing in Marysville had European trees nearby. They really cooled the fire down when it reached them

Steve

8/10/2019 07:49:50 am

Hi Ingilis
Yes these first hand accounts of fire behaviour provide valuable insights.

Steve

16/12/2019 09:54:28 pm

Hi great article thanks!
As a permaculture enthusiast in mid north coast NSW this is exactly what I’ll be doing soon!
We just had the fires go through our area and fortunately no loss, so I hope to be starting this ( once it eventually rains again) coming into the cooler months.

This land is red cedar land (toona ciliata), are they useful as a fire break planting?

I also noticed the brackenfern in the fields (I think that’s what they are) didn’t really burn and quite possibly slowed the fire in that area along the open sections.

Steve

18/12/2019 04:00:35 pm

Hi Steve,
That must have been frightening having the fires so close to your home. Those experiences make us think more rationally about the risks of choosing to live where we live.

I've done some background reading on Toona ciliata an it looks like a useful tree for permaculture, providing a good quality honey, timber and even aromatic oils from the fruit. Agroforestry expert Rowan Reid features it in his new book 'Heartwood'.

As to its value as a fire break, this Hawaiian reference suggests that it is, http://old.worldagroforestry.org/treedb2/speciesprofile.php?Spid=1649 However further research would be advisable before you rely on the Red Cedar to protect your property.

Good luck with your planting and well done on recognising the value of deciduous trees as an agent of protection in fire prone areas.

Ron

29/12/2019 07:41:59 pm

Hi.
And I can't understand why these trees are being planted throughout Australia?

Steve

31/12/2019 02:33:44 pm

Hi Ron,
I think you're agreeing that planting deciduous trees in rural areas to protect homes makes a lot of sense.

In most fire situations deciduous trees will make a valuable difference slowing the spread of fire by reducing wind speeds. They will also trap and cool embers which is a great asset to have around your home.

People may be torn between protecting their homes and protecting the natural areas that attract them to the country. Both objectives can be achieved with sensible and practical design

KarinP

31/12/2019 11:46:08 am

Great, timely read

Steve

31/12/2019 02:46:35 pm

Thanks Karin,
Its horrifying watching the country burn isn't it. We need a well thought through strategy to make people safe while living in the country. This would include both landscape design with fire retarding gardens and living environment design to minimise fire risk and to provide safe refuge on very severe days.

Thoughts and prayers from our PM are pitifully inadequate. Lets hope this fire season shakes our politicians into action.

Jane

9/1/2020 12:26:33 am

What an excellent, informative article thank you and it makes so much sense. Like many practical things I cannot understand why 'the powers that be' cannot listen & incorporate these simple systems into how we can best protect this country and ALL who live in it. The best that many of us can do is to do the best we can in our own worlds & every bit counts. This includes sharing this and other factually based information far & wide, surprisingly I only came across this article/way of thinking today.

One thing I would like to know is who do places like the Adelaide Hills SA & Macedon Ranges VIC burn so frequently & thoroughly? They are areas with lots of deciduous trees.

Keep up the excellent work and yes, where are the PhD students?? We need you!

Steve

9/1/2020 02:38:54 pm

Hi Jane,
The clear message that's coming through from conversations about these tragic fires is that its largely up to individuals and communities. The conservative nature of the powers that be will result in very slow change.

Interestingly one commentator on the ABC who was discussing the Traditional Owner (TO) cool burning method, suggested that we would save more lives and homes if we concentrated TO burns around private properties. Fuel reduction burns in forests are labour intensive and are becoming more difficult because the preparation season is shorter. Part of the answer therefore lies in training the community to do TO cool burns around their own properties.

The answer to your question about deciduous trees not preventing fires in the Macedon Ranges and the Adelaide Hills would be found in the microcosm of a fire.

A study would likely reveal that areas near deciduous trees had fires with a lower intensity, but the pattern of planting didn't provide an adequate overall barrier to stop a fire.

Its a complex question and the solution is also complex. I've tried to put fire protection into a four part package in my January 2020 blog on bushfires.

Ruth Kessler

13/1/2020 12:30:28 pm

I started planting my 5 acres over 30 years ago. I retained natural bush and trees and placed the deciduous trees in an ember catching net around the house half acre. Should also help with radiant heat. I also have about 3 half acres of paddock grass that if not mowen or eaten into the ground will stay green This is not possible in many areas. Being in the Dandenongs [bush fire central] this was a solution I saw work on Ash Wednesday at Mt Macedon. Where the big leafy trees saved many of the old homes. Even a huge Laurel hedge protected a 100 yr old cottage when the rest of the street went up. My assumption was Laurel would be very flammable but in this case seemed not. Have passed your article on.

Steve

13/1/2020 01:27:44 pm

Hi Ruth,
Your decision to plant deciduous trees around your house 30 years ago was both visionary and practical. You must be feeling more secure in a fire prone area knowing that you have these trees working for you - keeping you cooler and safer in the summer months. ...and there is the aesthetics.

Thank you for those great observations of houses protected at Mt Macedon on Ash Wednesday by deciduous trees and a Laurel hedge. I imagine the Laurel Hedge was well maintained and didn't have any dead flammable wood in its inner structure

Mary

22/1/2020 07:11:50 pm

Hi Steve,

I had already read and heard first hand experience regarding the planting of European trees to protect houses in instances of fire. My husband and I always knew we wanted to surround our house with beautiful deciduous trees. However recently I've been told the effects can be disastrous near river ecology systems. What are yours views with regards to how European trees effect riparian zones? We have a lovely little creek on the property and I've heard from people down the road that the ecosystem is suitable for Platapus. I wouldn't want to adversely effect it. There is a riparian zone of 30m which is well into the property, and my understanding is you should not build or interfere with the vegetation on these bits of land. Our house is more or less exactly 30m from the creek with a steep bank on the other side from the creek, not very suitable for planting large trees.

Steve

23/1/2020 05:34:23 pm

Hi Mary,

I agree that its important to protect and maintain the natural mix of indigenous tree and shrub species in the riparian zone along your creek. Your concerns for the Platypus are well placed as they are another Australian icon in trouble because of dwindling habitat. Having it 30m wide is particularly beneficial for all wildlife, but this will make your house more vulnerable in a fire.

If the creek is in your fire sector, to the north or west, I would consider thinning the native trees and shrubs so that the space between their outer foliage is equal to their height. Therefore a 2 m tall shrub would have 2m between the outer foliage and a 20m tall tree would have 20m between the outer foliage. This reduces the risk of fire jumping from plant to plant or tree to tree.

You may be familiar with the term 'ladder fuels'.- fires move upwards from grasses to shrubs to trees. Keep this in mind also if you decide to do some thinning along the creek.

Having said all that, it may still be possible to include smaller deciduous trees 10 m from the house as a fire barrier (3 - 7m tall). The concern about deciduous trees is because of the nutrient load from fallen leaves that they release into the creek each autumn. This could pollute the water and change its pH.

You should be able to trap these fallen leaves with wire netting or rake them to place elsewhere in your vegetable garden or orchard. I think it is also important to avoid deciduous trees that can become weedy and spread along the creek.

If the creek isn't in your fire sector, you have more scope to plant several rows of larger deciduous trees as a fire barrier

Dinah

26/1/2020 06:30:15 pm

Thank you for the great article Steve, and the site, which I have just discovered today. I look forward to exploring it further. I'm wondering whether you think native deciduous trees such as white cedar would have the same properties in terms of serving as a firebreak. I note the information above on the red cedar - I believe they are of a different family? Also wonder about the semi-deciduous Illawarra flame tree. Thanks.

Steve

29/1/2020 12:59:30 pm

Thanks Dinah,

Yes White Cedar, Melia azedarach; appears to be quite a useful fire retardant tree. I see that its listed on The Australian Plants Society's list of 'Fire resistant and Retardant plants'. It also has the benefit of being very drought resistant and the berries can be used to make an organic insecticide.

The illawarra flame tree, Brachychiton acerifolius; and others of the kurrajong family are also useful fire retardant tree species. I found a number of references recommending then after a quick google search.

Marilyn

19/2/2020 07:15:19 am

Thanks for your article, Steve. Our home and 3.4 acre garden was destroyed in the NYE bushfires, and the only vegetation which has survived has been the deciduous ornamentals. Sadly, these were not located in a position which could protect our home. To the north, an area which sloped gently then steeply away from the house, we had removed as many of the turpentines and eucalypts as originally permitted and we maintained the ground underneath well, but these trees acted as a catalyst rather than a protective barrier. ( The original Council/ RFS assessment 15 years ago wanted these trees to remain to trap embers). At least now, thanks to their total destruction, we can create the three layered deciduous tree barrier we wanted before! It’s a shame it has taken so long for knowledge to catch up - our initial preference was aesthetic, but in hindsight would also have been intelligent and may have saved our home.

Steve

21/2/2020 07:32:19 pm

Hi Marilyn,
I'm so sorry to hear that your home and garden were destroyed in the recent bushfires. It takes years of dreaming, planning and hard work to establish a home in the country and to lose it so cruelly to fire must be very difficult to come to terms with.

I think your plans to plant a barrier of deciduous trees to protect your future new home is full of hope and makes so much sense. You will feel safer knowing those trees will cool the air, reduce radiant heat and trap & extinguish embers.

Also consider building a house that is bushfire safe. There is plenty of information on the internet to get you started. The safest house (and the most energy efficient) you could build is underground with windows to the north protected by fireproof shutters

Brett

11/6/2020 04:19:09 pm

Hi Steve,
Thanks for sharing your observations and experience.
After Black Saturday, past Marysville near Cambarville, there is a 1,000 acre preservation of original forest, towering Mountain Ash, understory of local rainforest species, Myrtle Beech and Sassafras, where the fire stopped.
Have you investigated the uses of local rainforest species planted on contour swales to hold moisture in the landscape and act as fire breaks?

Steve

22/6/2020 11:54:27 am

Hi Brett,
That's a really important observation about the original forest near Cambarville stopping the 2009 fires. I wasn't aware of this so thank you for taking the time to send it through.

Mountain Ash, Myrtle Beech and Sassafras are unaccustomed to burning and historically wouldn't have supported fire. Frequent fires will permanently wipe out Mountain Ash as they take about 15 years to mature, flower and produce viable seed.

Also the Brigalow dry forests of southern Queensland don't support fire. These forests are predominantly of large acacias like the Brigalow (Acacia harpophylla) and other non flammable species. This style of vegetation was much more widespread until the end of the last ice age, making Australian forests much less flammable. You could read my blog on the Vegetation of the Barrabool Hills Part 2 to get more background on Australia's transition to 'fire loving' plants. If you copy and paste the link below into your search engine it'll take you there -

https://www.recreatingthecountry.com.au/blog/the-barrabool-hills-vegetation-part-2-the-arrival-of-homo-sapiens

laurence anderson

15/6/2020 05:05:38 pm

I have been saying for year that deciduous trees should be the only planting in towns and round houses. In addition, if the 50m either side of highways was planted with deciduous tees the timber would be valuable and fires easier to control. They could also be used as firebreaks; eg in a belt a kilometre wide.

Steve

22/6/2020 12:10:27 pm

Hi Laurence,
I agree that planting deciduous trees as fire barriers around houses and through towns as street trees would significantly reduce fire risk and intensity where in rural areas.

Your suggestion of 50m wide plantations of deciduous trees along highways would also be an effective measure, though for ecological and practical reasons I would find it difficult to support.

I think a more acceptable answer to the danger posed by native vegetation is to adopt Traditional Owner cool burning practices Australia wide. Fires were far less dangerous when they managed it with regular cool burns. I've developed this idea in my January blog 'Bushfires 2020 - making families safe in their country homes;

https://www.recreatingthecountry.com.au/blog/bushfires-2020-how-can-we-make-living-in-the-country-safe

Randy

19/6/2020 01:48:51 pm

Eucalyptus trees are a major fire hazard in California. At least one fire in Los Angeles was started from a power line sparking directly into a eucalyptus tree, which are not native to North America.

Steve

22/6/2020 12:20:48 pm

Hi Randy,
Eucalypts have been planted around the world because they are fast growing and a useful tree. As your comments indicate the decision to import plants from other countries can often lead to significant problems. Its a foolish mistake we continue to make unfortunately

Powerline Protection link

17/7/2020 05:25:14 pm

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Kemble link

23/8/2020 08:46:46 pm

Hi Steve thanks for a great article

Your info matches what I saw in the aftermath of fires coming through batlow last summer. Firebreaking around deciduous trees was evident in a few places but there weren't enough examples to really study. Most people focused on clearing firebreaks by removing trees and overgrazing

Native eucalypt and pine/blackberry forests were massively flammable of course. Eucalypt forest bounced back and looks pretty happy but the pine and forestry corp are a bit sad. Not sure about mountain ash

Wondering why you wouldn't support deciduous forestry as profitable firebreaking? Blokes love getting paddocks down to bare dirt so it won't burn but then the fertility of the soil disappears. How are we meant to farm if the expectation is to destroy soil fertility every summer?

If that's really the firefighting strategy for this decade, I don't believe we will be able to support Australian food security let alone ag or forestry economies

From what I know, traditional owner burn strategies evidently worked. In those times, over many generations, reliable land management produced an environment capable of supporting a stable level of population that led to a rich cultural/spiritual tapestry of indigenous nations that lived here pre invasion, each with distinct cultures, languages, trading relationships and so on

Today, Australia has a much larger population to support. Partly we do this thanks to introduced plant species that give more nourishment with less effort from the farmer; partly we use increasing amounts of machinery, fossil fuels and fertilizers. N fert usage in Aus increased 5x in last 40 years. Unsustainable

The land management strategy suggested by TO burns, from what you've written above, is to let the euc forests burn, while creating open expanses with little to zero vegetation around homes and assets? I just don't see how this is compatible with farming.

By contrast, the deciduous firebreak model that you advocated in your earlier replies effectively protects against fire while also supporting the productive needs of a population 25 times (?+-) larger than in 1788. Did something happen to change your view?

Personally I would go further to suggest that we need to establish new settlements among forestry areas, with the purpose of maintaining the forest, reducing hazards, optimising timber growth .. and that we should broadly reforest entire regions with introduced species suited to the goals of increasing climate stability, biodiversity habitat, timber assets, and land fertility

Everyone benefits from more fertile land so it is weird to see the mental gymnastics arguing against it. On the other hand, pre-invasion land management is not capable of supporting everyone, so it's equally weird to see the almost uniform support for that... In my view there's a big karmic hoodoo about colonisation that's clouding the debate

Wouldn't it be better to establish new ecosystems of introduced species alongside and in harmony with native landscapes? Instead of shirking responsibility, and continuing to clear native forests for inefficient farm expansion and unsustainable logging?

These new forests will resist fire, provide sanctuary for biodiversity, regulate rainfall, sequester carbon, encourage aquifer recharge, produce timber... All while reducing pressure on native landscapes from ag/forestry/mining

I get that bare dirt around every house is extremely safe from fire, but it's not very safe in a drought when people are trying to eat food. And it puts more pressure on other regions that do produce food

Isn't it better to accept the help offered by introduced species and share the benefits among everyone? Obviously and of course we should preserve native ecosystems at the same time. Just as wollemi pine forest coexists with red cedar, with others.. we've already made a new botanical epoch, why not take responsibility for it and make something good out of it instead of pretending we can erase what happened?

Anyway, thanks for the thoughtful article and thanks for any enlightenment on the topic. I read every word and every comment here and am listening. I may not be the fastest learner but at least I'm not planting 10 million radiata pine like nsw forestry corp

Cheers and all the best

Steve

24/8/2020 12:10:46 pm

Hi Kemble,

I like the considered arguments that you're putting forward. Adding more deciduous trees around settlements as forestry plantations to the north and west of towns (instead of flammable Radiata Pine) would clearly provide protection from advancing fires. And there would be plenty of demand for the timber in the construction industry.

Its a matter of finding the right balance between conservation of flora and fauna and living safely in rural environments. I recognise that development in rural areas is putting constant pressure on the dwindling remnant vegetation with less than 1% of very fragmented grasslands and grassy woodlands left.

So how do town planners get their heads around this issue of providing more homes for an ever expanding population and protecting our unique botanical and biological heritage?

Just accepting that we will have hotter more dangerous fires as this century ticks over. To say 'business as usual' and not change the way we design homes, landscape towns and manage our remnant native bush would be madness.

I think your ideas are worth considering. Deciduous forestry in suitably high rainfall areas could pay an important part. Planting well placed deciduous trees on private property will provide important localised protection. Building fire resistant homes, ideally underground, would give families a reliable and safe refuge.

Traditional Owner burning would reduce the fire risk of the native bush around towns and would improve the biodiversity of the remnant bushland that remains.

How we manage areas in the national parks that are difficult to access is another big question. But its clearly time that we ask and listen to the Traditional Owners of this country and put them in the drivers seat, to quote Victor Steffensen (ref: 'Fire Country' - a great read)

Stanley Thomas link

1/10/2020 03:58:04 pm

Life always finds its way. It will thrive n grow back more amazing. It will just take time but it will be back beautifully.

Steve

4/10/2020 10:41:43 am

Thanks Stanley for those positive and uplifting sentiments. Its important to look forward to a future that offers us hope and beauty in nature. The Australian bush has clearly this ability to recover and thrive after adverse events like fire.

Jake Martin link

2/10/2020 12:19:57 pm

Your simplicity of presentation is motivating for learning. Please keep it up for your teeming followers.

Steve

4/10/2020 10:45:48 am

Hi Jake,
Its nice to know that my humble scribblings are comprehendable and helpful. I'm inspired by the many insightful and uplifting comments that arrive at my website. So thank you for all that you do.

Ken Wild

1/2/2021 06:43:59 pm

Hi Steve,
Your observations are astute. Purists seem horrified at replacing native trees with 'aliens' (and I'm not too happy about it either!), but I suspect the overwhelming force of climate change will render the argument redundant. Repeated fire events will inevitably result in the demise of local species - as has surely occurred many times over the last 70,000 years or so!

I think we need to be much more proactive - and realistic-in our approach to protecting our ecology (flora/fauna). While TO burns might be effective, they appear to be very resource-intensive and risky. In contrast, deciduous tree belts can grow unattended for decades. And if they're productive trees (nuts/fruit/timber), they can also provide a renewable source of income for locals that doesn't involve destroying further habitat.

Steve

4/2/2021 02:40:10 pm

Thank you for those great comments Ken,
I had an indigenous nursery for over thirty years and was a founding member for three friends groups set up to protect indigenous flora. So I understand very well how horrified the purists would be.
Though I'm also a pragmatist and agree that deciduous fire barriers would also benefit indigenous flora by reducing the damage of bushfires.
I would start by planting deciduous fire barriers around private homes and also as closely spaced shade trees in country towns and in peri-urban areas. As the climate warms the cooling effect provided by these deciduous street would be of great benefit to rural communities. I agree that other products could also be harvested - this is what the founder of Permaculture Bill Mollison was proposing nearly fifty years ago so it's certainly not a new idea.
I'm an active supporter of TO burning but I think its going to take some time before it becomes an accepted and common practice. I hope I'm wrong because its an effective method that would benefit the whole nation.

Glen Walling

25/2/2021 11:39:42 pm

Not at all a new concept. In Bill Mollison's Designers Manual (1988) It discusses this very issue. Like all great ideas and people who come up with them they are either dismissed, ignored or attacked by those with a vested interest or cannot see beyond their own paradigms.
Mollison doesn't try to tell you what to think more he tries to tell you how to think.

Steve

26/2/2021 11:57:48 am

I agree absolutely Glen,
Mollison was a remarkable visionary and I subscribed to his ideas for a decade or so. I just couldn't agree with permaculture's gung ho approach of planting potential weeds everywhere without understanding their ability to spread and become a serious problem in indigenous flora reserves (Tree Lucerne, Cytisus proliferus, a permaculture fodder plant for example, is a very invasive weed)
Sometimes a good idea has to be repeated over and over to get people's attention and sometimes its simply the right idea at the right time. Cheers

Recreating the Country blog

Deciduous trees can provide crucial bushfire protection in rural Australia

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